1. Field of the Invention
The present invention relates generally to a liquid crystal display overdrive device and method thereof, and in particular to an overdrive accuracy adjustment device and method thereof for obtaining improved response speed of the liquid crystal display and also better image quality.
2. The Prior Arts
Referring to FIG. 1A to FIG. 1B, a conventional drive method is shown in FIG. 1A to FIG. 1B. As shown in FIG. 1A in the conventional drive method, when a grayscale value of g0 is switched into g1 at time t0, the corresponding pixel brightness is switched from Y0 into Y1. However, the response time during the switching of the pixel brightness from Y0 to Y1 is exceedingly prolonged such that the pixel brightness cannot reach the predetermined Y1 within a pixel period.
As shown in FIG. 1B, the overdrive method has been disclosed to overcome the problem as mentioned above. The pixel brightness can reach the predetermined Y1 within a pixel period. In this pixel period, the overdrive grayscale value (g1′) required by the overdrive would be related to the previous grayscale value (g0) and the current grayscale value (g1).
Referring to FIG. 2A to FIG. 2C, a conventional drive device is shown in FIG. 2A to FIG. 2C. As shown in FIG. 2A, a conventional drive device includes a look-up table 10 for the 3 gamma values, a memory controller 12, a memory 14, and an overdrive module 16. The conventional device constructed by the overdrive module 16 can perform the overdrive as shown in FIG. 1B. The look-up table 10 (for 3 gamma values or the gamma curve) converts the grayscale values received to the proper drive voltages. And then the memory controller 12 receives the pixel values from the look-up table 10 and stores the pixel values inside the memory 14. The overdrive module 16 receives the current grayscale value (g1) and the previous grayscale value (g0) from the look-up table 10 (holding the gamma values) and the memory controller 12, respectively, to look up the corresponding overdrive grayscale value (g1′) in a built-in look-up table 18, and uses the results inside a liquid crystal display panel.
As shown in FIG. 2B, the look-up table 18 includes a plurality of current grayscale values and a plurality of previous grayscale values which are mutually corresponding to a plurality of overdrive grayscale values. Taking the 256 grayscale as an example, 256×256 overdrive grayscale values would be stored in the look-up table 18. However, under general applications for the sake of reducing storage costs, the quantity of the overdrive grayscale values stored in the look-up table 18 may be only 21×21. In other words, only overdrive grayscale values which are corresponding with a plurality of current grayscale values and a plurality of previous grayscale values having grayscale values of 0, 4, 8, 12 . . . are stored. If it is required to look up the current grayscale value for 21 and the previous grayscale value for 6 as shown in FIG. 2C, interpolation operation is performed.